SAN DIEGO, Calif. — Missing a single night of sleep can leave the brain anxious the next day. That’s the finding of a new study from the University of California, Berkeley.
Sleep researchers Eti Ben Simon and Matthew Walker invited healthy adults to sleep overnight in their lab. Whether someone slept or not affected their anxiety in the morning. A wakeful night also changed patterns of brain activity.
The scientists reported these results November 4 at the annual meeting of the Society for Neuroscience, in San Diego, Calif.
People with anxiety disorders often have trouble sleeping. The new results show the reverse may be true, too: Poor sleep can lead to anxiety.
“This is a two-way interaction,” says Clifford Saper. He works at Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, Mass. He studies sleep but wasn’t part of the new study. “Sleep loss makes the anxiety worse,” he notes, “which in turn makes it harder to sleep.”
The new study enrolled 18 healthy volunteers. They either got a full night of sleep or stayed up all night. The next morning, each person took a test to gauge signs of anxiety. They also laid in a brain scanner and watched short videos. These were designed to spark emotional reactions. The scanner recorded patterns of brain activity as the volunteers watched.
On a different night, the volunteers switched groups. Those who slept the first time now had to stay up all night. The previously sleep-deprived people got some shut-eye. The next morning, each repeated the anxiety test and brain scan.
Sleep makes a big difference, those tests showed. Staying awake all night boosted anxiety levels 30 percent above those that were typical after getting a night’s sleep. Just one sleepless night boosted anxiety in healthy recruits to levels seen in people with anxiety disorders. Ben Simon described that finding November 5 to news reporters at the conference.
What’s more, brain activity in sleep-deprived people was different. Parts of their brains involved in emotions were more active than usual when they watched emotional videos. And an area that can put the brakes on anxiety, known as the prefrontal cortex, was less active than normal.
The results suggest that poor sleep “is more than just a symptom” of anxiety, Ben Simon says. In some cases, it may help cause the condition.
annual Adjective for something that happens every year.
anxiety A nervous reaction to events causing excessive uneasiness and apprehension. People with anxiety may even develop panic attacks.
brain scan A technique to view structures inside the brain, typically with X-rays or a magnetic resonance imaging (or MRI) machine. With MRI technology — especially the type known as functional MRI (or fMRI) — the activity of different brain regions can be viewed during an event, such as viewing pictures, computing sums or listening to music.
disorder (in medicine) A condition where the body does not work appropriately, leading to what might be viewed as an illness. This term can sometimes be used interchangeably with disease.
gauge A device to measure the size or volume of something. For instance, tide gauges track the ever-changing height of coastal water levels throughout the day. Or any system or event that can be used to estimate the size or magnitude of something else. (v. to gauge) The act of measuring or estimating the size of something.
neuroscience The field of science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.
prefrontal cortex A region containing some of the brain’s gray matter. Located behind the forehead, it plays a role in making decisions and other complex mental activities, in emotions and in behaviors.
recruit (noun) New member of a group or human trial. (verb) To enroll a new member into a research trial. Some may receive money or other compensation for their participation, particularly if they enter the trial healthy.
symptom A physical or mental indicator generally regarded to be characteristic of a disease. Sometimes a single symptom — especially a general one, such as fever or pain — can be a sign of any of many different types of injury or disease.
Meeting: E. Ben Simon and M.P. Walker. Underslept and overanxious: The neural correlates of sleep loss-induced anxiety in the human brain. Society for Neuroscience Annual Meeting, San Diego, November 4, 2018.